In the prior art, for example Shockey et al. U.S. Pat. No. 4,994,033 and the C. R. Bard Inc. European Patent Application No. 383,429A2, published Aug. 22, 1990, a catheter is taught for the application of medication to a blood vessel wall, for example to a stenosis. The medication is administered through a balloon in the catheter which carries an array of minute holes or micropores, so that the medication may flow into the balloon through a lumen in the catheter, and then by the action of pressurization in the balloon it is forced out of the holes or micropores.
It has been found that at pressures of about two atmospheres and above, the velocity of fluid that passes out of the holes of such a balloon often can create a forceful stream which directly impinges the arterial wall. This, in turn, can actually cause tissue damage, even to the extent of extending and increasing a dissection within the arterial wall which is caused by an angioplasty procedure such as PCTA.
Thus there is a need for an infusion balloon catheter for administering medication to the arterial wall in which the medication can be administered under a reasonable pressure for rapid flow of medication out of a single perforated balloon, but the forceful streams are avoided, so that the fluid does not forcefully impinge against the arterial wall, but rather it diffuses out of the perforations in a substantial but non-damaging manner.
Baran U.S. Pat. No. 4,417,576 discloses a double-wall surgical cuff in which a surgical fluid such as an anesthetic may be inserted in a sponge rubber material emplaced between the two surgical cuffs. The outer surgical cuff is perforated, so that the surgical fluid can pass out outwardly through the outer surgical cuff, while the inner surgical cuff is not perforated. This relatively complex device may have a substantially increased outer diameter due to the presence of the two balloons and the sponge rubber, which restricts its entry into the smallest of arteries and the like.